ci: migrate from CircleCI to GitHub Actions (#321)

* ci: migrate from CircleCI to GitHub Actions

CircleCI has been unable to check out the repository since its checkout
key stopped working, so nothing has been deployed since 2023-10. Replace
it with GitHub Actions and publish through the Pages deployment API
instead of committing the build output to the master branch.

- add .github/workflows/deploy.yml (build on every push/PR, deploy to
  Pages on source)
- drop .circleci/config.yml and update.sh
- drop rimraf and status-back, only used by the two files above
- bump .node-version from 8.1.4 to 24, the current LTS
- fix bulbofile.js for the ESM majors of gulp-nunjucks and gulp-markdown
  pulled in by #312 and #313, which broke the build
- emit CNAME into build/ so the custom domain survives in the artifact

* ci: publish to master instead of GitHub Pages

nodejs.jp turns out to be served by Netlify out of the master branch, not
by GitHub Pages, so deploying through the Pages API would not touch the
live site. Replace the Pages deploy job with one that builds into a
checkout of master and pushes, which is what update.sh did under
CircleCI.

Author: kt3k

.circleci/config.yml

@@ -0,0 +1,68 @@
+name: build & deploy
+
+on:
+  push:
+    branches: [source]
+  pull_request:
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+# Let a running deploy finish rather than cancelling it half way.
+concurrency:
+  group: deploy
+  cancel-in-progress: false
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+      - uses: actions/setup-node@v7
+        with:
+          node-version-file: .node-version
+          cache: npm
+      - run: npm ci
+      - run: npm run build
+      # Uploaded on pull requests too, so the built site can be downloaded
+      # from the run page for review.
+      - uses: actions/upload-artifact@v7
+        with:
+          name: site
+          path: build
+
+  # nodejs.jp is served by Netlify out of the master branch, so publishing
+  # means committing the build output there. This mirrors the update.sh that
+  # CircleCI used to run.
+  deploy:
+    needs: build
+    if: github.event_name != 'pull_request'
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+    steps:
+      - uses: actions/checkout@v7
+      - uses: actions/setup-node@v7
+        with:
+          node-version-file: .node-version
+          cache: npm
+      - run: npm ci
+      - name: Check out master as the build destination
+        run: |
+          git clone --depth 1 -b master \
+            "https://x-access-token:${{ secrets.GITHUB_TOKEN }}@github.com/${{ github.repository }}.git" \
+            build
+      - run: npm run build
+      - name: Commit and push
+        working-directory: build
+        run: |
+          git config user.name 'github-actions[bot]'
+          git config user.email '41898282+github-actions[bot]@users.noreply.github.com'
+          git add -A
+          if git diff --cached --quiet; then
+            echo 'nothing to publish'
+            exit 0
+          fi
+          git commit -m 'chore(site): automated update from github actions'
+          git push origin HEAD:master

.github/workflows/deploy.yml

@@ -1 +1 @@
-8.1.4
+24

.node-version

@@ -3,8 +3,10 @@ const asset = bulbo.asset
 
 const path = require('path')
 const frontMatter = require('gulp-front-matter')
-const nunjucks = require('gulp-nunjucks')
-const markdown = require('gulp-markdown')
+// gulp-nunjucks v6 / gulp-markdown v8 are ESM. require() of ESM is supported
+// on Node 22.12+ so we read the named / default exports off the namespace.
+const {nunjucksCompile} = require('gulp-nunjucks')
+const markdown = require('gulp-markdown').default
 const wrapper = require('layout-wrapper')
 const accumulate = require('vinyl-accumulate')
 const branch = require('branch-pipe')
@@ -35,7 +37,7 @@ const layout = defaultLayout => wrapper.nunjucks({
 asset('source/**/*.md', '!source/{events,jobs,news}/**/*')
   .watch('source/**/*.{md,njk}')
   .pipe(frontMatter({property: 'fm'}))
-  .pipe(nunjucks.compile(data))
+  .pipe(nunjucksCompile(data))
   .pipe(markdown())
   .pipe(layout('default'))
 
@@ -128,3 +130,7 @@ asset('source/pdfs/**/*.pdf')
 
 // Old site is available under http://nodejs.jp/old/
 asset('./old/*.*').base('./')
+
+// Keep CNAME in the published output rather than relying on the copy that
+// happens to sit in master
+asset('./CNAME').base('./')